Free coal heating in northern China had dramatic health consequences.

Coal is the least efficient of the fossil fuels in terms of the amount of energy gained vs. CO2 released. Burning it also releases numerous toxic chemicals and particulates, which can exact a cost on a country's population in terms of reduced life expectancy and increased health costs. Figuring out the exact cost of coal use, however, is challenging because of a combination of different pollution controls and the mobility of the population.

Thanks to an unusual combination of policies (some completely unrelated to pollution), China has accidentally provided the opportunity to put an exact number on the human cost of coal use. And that number turns out to be staggering: 5.5 years of reduced life expectancy that, when spread over the half-billion people of northern China, means a loss of 2.5 billion life-years.

The Huai River line

There are two key policies that turned China into a giant natural experiment on the impact of coal. The first is that, until recent years, China has had laws in place that severely limited the mobility of its citizenry. People didn't tend to move around, so they continued to live (and die) near the site of their exposure. That makes lifetime exposures easy to estimate, and it ensures that local health and mortality records could be directly connected to these exposures.

Second, starting in 1950, the Chinese government divided the country along the Huai River, which roughly traces the line where winter temperatures are, on average, freezing—and north of that line, everyone was eligible for free, coal-powered heating. The line cuts across a variety of provinces and political divisions, so there's little else about China that's likely to be divided in the same way.

China uses coal for a variety of purposes beyond heating—with the result that, as the authors of a new study note, current particulate levels in China are five times what they were in the US back in the 1960s, prior to the passage of the Clean Air Act. (These levels are, incidentally, twice the limits allowed under Chinese law.) Despite the existing overall high levels of pollution across the country, the addition of this much heating-related coal burning had a significant impact on the air quality of northern China over the last half century. By 2000, as one crossed the Huai River line, the total particulates in each cubic meter of air jumped by nearly 200 micrograms.

Exposure to particulates has a variety of negative consequences, primarily on the lung and cardiovascular systems, so the authors classified all deaths in 90 Chinese cities between 1990-2000 and collected additional demographic information that covered factors that are associated with life expectancies. Then they ran it all through a statistical model that took into account each city's distance from the Huai River. Their model suggests that life expectancies north of the river line are 5.5 years lower than they are to the south (although their 95 percent confidence interval is rather large). Their estimate suggests that every 100 micrograms of particulates in a cubic meter of air drops life expectancy by about three years.

Based on this drop in life expectancy, the authors calculate a total loss of life for the half-billion citizens that live north of the line as 2.5 billion years of life lost prematurely.

The authors do note that the free coal provided by the government would likely alter behavior in a variety of ways, some of which could influence health. People might spend more of their year indoors, get less exercise, have more disposable income, etc. Still, the magnitude of the effect is rather large and is consistent with what we know about the health impacts of particulates.

China is just beginning to grapple with its heavy use of coal and its lack of pollution controls. But the installed base of coal-burning hardware, from large plants to individual homes, remains enormous, which means that there will be a long legacy of health problems inherited from earlier policy decisions.

84 Reader Comments

It seems like the study is leaving out the gains in life expectancy that have come from coal-powered industrialization.

I did a quick search and found that life expectancy in China in 1950 was under 40, now it's about 75 years.

Of course I would not give coal 100% credit for the increase, but at the same time it seems that the authors are missing the forest for the trees; what do they think life expectancy in China would be like if they weren't burning any coal at all?

How can you extrapolate the decrease in life expectancy due to coal-burning in cities to the countryside? Surely the pollution is more spread out in the country and hence less damaging.

In other words, if I burn 1 kg of coal, and the 100 other people in my street also burn 1 kg of coal, I am (very roughly) exposed to the particles from 100 kg of coal. If, however, my nearest neighbour lives 10 km away, I am more likely to be affected only by the particles from my own 1 kg.

So the -5.5 years of life expectancy in the cities is sure to be greater than what happened in the country, ceteris paribus.

It seems like the study is leaving out the gains in life expectancy that have come from coal-powered industrialization.

I did a quick search and found that life expectancy in China in 1950 was under 40, now it's about 75 years.

I don't think that was the point of the study. They were trying to determine the effect of coal's pollution, and China turned out to have the right characteristics to allow them to control for the non-coal variables that affect life expectancy.

That coal might have provided another benefit is an interesting point, but is irrelevant to the study. Even so, it's industrialization that you're giving credit to. Coal was not the only possible fuel source for that industrialization.

I did a quick search and found that life expectancy in China in 1950 was under 40, now it's about 75 years.

You're not adjusting for localization. That life expectancy may be true for a highly urban apartment or condo dweller, but it sure as hell isn't true for a rural, isolated laborer.

No, but it is average. 40->75 is a huge leap, with a population as large as China's, that doesn't come from 5 guys living in high rise apartments above the smog and living to 1000.

Forty to seventy-five covering years 1950-2013 has nothing to do with the study in the first place, which measured effects from 1990-2000. Look up life-expectancy in that range and let me know the delta.

Quote:

so the authors classified all deaths in 90 Chinese cities between 1990-2000 and collected additional demographic information that covered factors that are associated with life expectancies

It seems like the study is leaving out the gains in life expectancy that have come from coal-powered industrialization.

I did a quick search and found that life expectancy in China in 1950 was under 40, now it's about 75 years.

Of course I would not give coal 100% credit for the increase, but at the same time it seems that the authors are missing the forest for the trees; what do they think life expectancy in China would be like if they weren't burning any coal at all?

They think the life expectancy in China would be like what it currently is south of the Huai River line. So, the comparison already takes into account advancing technology and industrialization, which occurred both north and south of the river. It's that internal comparison between different parts of the country at the same times that makes the comparison so powerful.

How can you extrapolate the decrease in life expectancy due to coal-burning in cities to the countryside? Surely the pollution is more spread out in the country and hence less damaging.

In other words, if I burn 1 kg of coal, and the 100 other people in my street also burn 1 kg of coal, I am (very roughly) exposed to the particles from 100 kg of coal. If, however, my nearest neighbour lives 10 km away, I am more likely to be affected only by the particles from my own 1 kg.

So the -5.5 years of life expectancy in the cities is sure to be greater than what happened in the country, ceteris paribus.

Yes, I didn't like this either. The article clearly points to studying cities, which will have more air pollution due to higher population levels, proximity of factories, urban traffic, etc. Extrapolating out to the entire rest of the region seems like a sensationalistic grab at "OMG 2.5 billion years of death!"

So, if the government did something that cost $100 per person in the US, would you say that the cost of that was $100, or $30 billion? The number does seem to communicate the cost magnitude correctly because it provides balance to the fact that it impacts a large number of people.

(setting aside arguments about sensationalism, or whether the 5.5 years/person is valid in the first place)

EDIT: Put differently, if 5.5 years of damage were done to ten people, it is sad, but perhaps a small tragedy instead of a catastrophe when done to millions...

How can you extrapolate the decrease in life expectancy due to coal-burning in cities to the countryside? Surely the pollution is more spread out in the country and hence less damaging.

In other words, if I burn 1 kg of coal, and the 100 other people in my street also burn 1 kg of coal, I am (very roughly) exposed to the particles from 100 kg of coal. If, however, my nearest neighbour lives 10 km away, I am more likely to be affected only by the particles from my own 1 kg.

So the -5.5 years of life expectancy in the cities is sure to be greater than what happened in the country, ceteris paribus.

I don't know if it's so simple as an inverse-square sort of relationship. The various wind currents probably play a large role in how pollution is disseminated amongst the population. If your rural village lives down wind from a coal power plant, you could be getting quite a bit of smog. Also, remember that city-dwellers will probably have better access to those goods which result from power distribution (such as improved healthcare).

But yeah, in the end, it's probably hard to say what the net effect is without doing the research.

It seems like the study is leaving out the gains in life expectancy that have come from coal-powered industrialization.

I did a quick search and found that life expectancy in China in 1950 was under 40, now it's about 75 years.

Of course I would not give coal 100% credit for the increase, but at the same time it seems that the authors are missing the forest for the trees; what do they think life expectancy in China would be like if they weren't burning any coal at all?

You're kinda forgetting about that whole Chairman Mao thing in that time period. He had a lot to do with the mortality rate being as high as it was.

It seems like the study is leaving out the gains in life expectancy that have come from coal-powered industrialization.

This! And only this. Yes coal is bad but what are the alternatives? Economic Growth has actually drastically increased life expectancy. And for growth you need energy. And even the rich countries have not managed to get their energy in a really clean way. Ecologists are awesome in saying what is bad but terrible in providing solutions

I spend about a week each quarter there. Last time was for two weeks in Shanghai. We were all light headed and dizzy the entire time and my immune system really began to crash. It's pretty clear, they're trying to kill everyone.

The upside is that it will probably kill off the old first and resolve their aging demographic problem...

The most of the coal pollution is from household stoves that burn coal cylinders, not from industrial sources. As natural gas and electric heaters become more available, people will switch to the cleaner fuel sources.

"China saves 2.5 billion years worth of geriatric care by killing off its elderly citizens earlier."

Euthanasia in action!

Children take care of the elderly in China, their mortality rate is of little concern to The Party (who already want the population growth to curb for a reason other than it being a nation full of dudes)

Ecologists are awesome in saying what is bad but terrible in providing solutions

Fair enough, but it's valuable information nonetheless. In many cases we do a poor job of prioritizing what we need to fix, and information like this is invaluable towards that goal. The two biggest questions are:

1. What are the costs of doing nothing?2. What are the costs of fixing the problem?

If #2 is greater than #1 (note there may be many potential solutions with varying costs and efficacies) it may well pay to do nothing. You still can't make a decision without a reasonable estimate for both though.

It seems like the study is leaving out the gains in life expectancy that have come from coal-powered industrialization.

I did a quick search and found that life expectancy in China in 1950 was under 40, now it's about 75 years.

Of course I would not give coal 100% credit for the increase, but at the same time it seems that the authors are missing the forest for the trees; what do they think life expectancy in China would be like if they weren't burning any coal at all?

There is no debate the economic prosperity of industrialization leads to gains in education, health care and nutrition which directly affects life expectancy. At this point in time with the knowledge the world has of coal it seems odd they would burn it so carelessly. The country has grown magnificently in many categories but why is its heat and electricity generation stuck? I guess everyone goes through the same steps.

It seems like the study is leaving out the gains in life expectancy that have come from coal-powered industrialization.

This! And only this. Yes coal is bad but what are the alternatives? Economic Growth has actually drastically increased life expectancy. And for growth you need energy. And even the rich countries have not managed to get their energy in a really clean way. Ecologists are awesome in saying what is bad but terrible in providing solutions

As JDale says, the south is the control. it also industrialized and has similar urban / country ratios, but less domestic use of coal,You might be surprised how far into the countryside the air quality extends. I flew from Beijing to Xi'an. Took off in haze, flew over haze, landed in haze. On a fast train from Beijing to Shanghai it was almost an hour before the air cleared enough to be interesting to see the countryside.

Also, the coal use is personal. People can get free coal to take home so they are creating smoke near or in their homes whether in country or city. Many country "villages" in China are high rise or dense construction (imagine putting 1.2Bn people in the USA east of the Mississipi for an idea of what to expect) so would not expect country stats to be better than city. Might even be worse in rural areas due to use of simpler heating in older homes.

I don't know, I thought the headline was pretty somber. Think of all those man-hours that could be used towards something productive. It takes a lot of effort to raise a human being. If you're cutting a life short 5 years, that's 5 less years productivity you're getting out of them when they're already trained, employed, caring for a family, working on hobbies, etc. (I don't mean "productive" in a slave-driver sense, I mean a broad-scoped sociological sense, where the impact of that person on society as a whole is cut short).

Also, first comment brought up life expectancy, but life expectancy must get measured against quality of life. No point living 30 years extra if you're debilitated with black lung, and a burden on the health care industry of the country.

The most of the coal pollution is from household stoves that burn coal cylinders, not from industrial sources. As natural gas and electric heaters become more available, people will switch to the cleaner fuel sources.

It seems like the study is leaving out the gains in life expectancy that have come from coal-powered industrialization.

I did a quick search and found that life expectancy in China in 1950 was under 40, now it's about 75 years.

Of course I would not give coal 100% credit for the increase, but at the same time it seems that the authors are missing the forest for the trees; what do they think life expectancy in China would be like if they weren't burning any coal at all?

This study is only about burning coal in the home for heating. All the other effects of coal in the economy should be roughly equal between the two zones.

The study doesn't say "life expectancies in China are 5.5 years lower than before they started burning coal". The study says "life expectancies where coal is free for home heating are 5.5 years lower than where coal is not free for home heating". The fact that life expectancy almost doubled since the 1940s is otherwise true for both areas.

It should be noted that even with the relatively low emissions standards in China, it is dramatically cleaner to burn coal industrially than in the home. This is especially true if your home heating coal is provided free by the government (less incentive to make sure it is burning as hot/thoroughly as possible). So it's not simply the case that more coal is burned in those areas with the subsidies. You also end up with more pollution per pound of coal burned. Double-whammy.

For a country that is actively trying to reduce its population (one child policy), it would seem reducing the lifespan of the current population is a positive thing for China as well.

Interesting how this article paints this topic in a negative light. Does the author take the same view of the one child policy?

Yeah, well, except for that little detail of many of those people coming down with expensive chronic diseases that have to be treated prior to their premature demise. Or maybe you think they should be euthanized when they start to develop a cough?

How can you extrapolate the decrease in life expectancy due to coal-burning in cities to the countryside? Surely the pollution is more spread out in the country and hence less damaging.

In other words, if I burn 1 kg of coal, and the 100 other people in my street also burn 1 kg of coal, I am (very roughly) exposed to the particles from 100 kg of coal. If, however, my nearest neighbour lives 10 km away, I am more likely to be affected only by the particles from my own 1 kg.

So the -5.5 years of life expectancy in the cities is sure to be greater than what happened in the country, ceteris paribus.

They probably compare like-to-like. Rural north of the line to rural south of the line. Urban north of the line to urban south of the line. I haven't seen the study, but they probably have more detail than just the 5.5 years average. My guess is that the 5.5 years is really something like 7 years for urban dwellers and 4 years for rural dwellers (exact figures are guesses, but I'd be surprised if they don't break it down in the study).

EDIT: Oops. I missed the point that they only analyzed the cities. Ignore me. I only didn't delete this post because it had been up for long enough that it felt wrong to totally delete it.